a) For each of the following acid solutions, predict whether the “x is small” approximation is valid (write yes or no for each solution). 

i) 0.006 M hydrofluoric acid (K_a = 6.8 x 10^-4)

ii) 1.0 M  hydrocyanic acid (K_a = 4.9 x 10^-10)

iii) 0.10 M chlorous acid (K_a = 1.1 x 10^-2)

iv) 0.30 M acetic acid (K_a = 1.8 x 10^-5)

b) Calculate the pH of a 0.30 M acetic acid solution. 

c) For each of the following mixtures, predict whether we can ignore the contribution of the weaker acid to the overall pH (yes or no).

i) 0.010 M nitric acid + 2.0 M chlorous acid

ii) 1.0 M hydrofluoric acid + 0.20 M hydrocyanic acid

iii) 0.30 M hydrofluoric acid + 0.40 M acetic acid

iv) 1.0 M chlorous acid + 1.0 M hydrocyanic acid

d) Calculate the pH of a mixture that is 0.010 M nitric acid and 2.0 M chlorous acid.